CVE-2021-1279Network attack vector

Unauthenticated service interruption via crafted SNMPv3 traffic

Published Jan 20, 2021 · Updated Nov 12, 2024

Denial of service in Cisco SD-WAN SNMPv3 management allows remote attackers to interrupt affected controllers and routers. The SNMPv3 management path insufficiently validates crafted protocol traffic before processing it on vBond, vEdge, vManage, and vSmart systems. No credentials or user interaction are required; the documented consequence is service interruption without data access or modification.

CVSS severity5.3
Medium
EPSS probability1.39%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in Cisco SD-WAN SNMPv3 management allows remote attackers to interrupt affected controllers and routers. The SNMPv3 management path insufficiently validates crafted protocol traffic before processing it on vBond, vEdge, vManage, and vSmart systems. No credentials or user interaction are required; the documented consequence is service interruption without data access or modification.

The record

CVE
CVE-2021-1279
Published
Jan 20, 2021
Updated
Nov 12, 2024
Vendor
ClamAV
Product
Cisco SD-WAN
Classifications
CWE-20, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 20, 2021CVE publishedPublication date reported by the CVE source.
  2. Nov 12, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=n/a

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

ClamAV · Cisco SD-WANversion=n/a

Published CVSS scores

7.8NVDAV:N/AC:L/Au:N/C:N/I:N/A:C
5.3CiscoCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-20Improper Input Validation
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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